This is an inofficial mirror of http://metamath.tirix.org for personal testing of a visualizer extension only.
Description: Set exponentiation has a universal domain. (Contributed by NM, 8-Dec-2003) (Revised by Mario Carneiro, 8-Sep-2013)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | fnmap |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | df-map | ||
| 2 | mapex | ||
| 3 | 2 | el2v | |
| 4 | 1 3 | fnmpoi |